Date of Award
Spring 1995
Document Type
Thesis - Restricted
Degree Name
Master of Science (MS)
Department
Electrical and Computer Engineering
First Advisor
Ishii, Thomas K.
Second Advisor
Jeutter, Dean C.
Third Advisor
Richie, James
Abstract
The objective of this thesis is to perform and compare time domain velocity measurement techniques using pulse modulated microwaves in waveguide. Open air velocity measurements were also performed to provide a basis of calibration. The experimental results derived from the experiments were analyzed to give further insight into the velocity of propagation of pulse modulated microwaves. It is well known that the theoretical phase and group velocities of non-TEM waves in rectangular waveguide are a function of frequency. Traditionally, it has been accepted in the scientific community that the phase velocity cannot be used to transmit information. However, it has been theoretically proposed that a part of the energy associated with the leading edge of non-TEM pulse modulated microwaves travels with the phase velocity in a waveguide. It was experimentally observed in this research that measurement techniques and procedures used in determining the signal velocity will affect the results. One technique presented, the direct transit time method, shows that the measured signal velocity versus frequency has a negative slope which corresponds to the phase velocity. However, using the same instrumentation with a different technique, the waveguide insertion method, the signal appeared to correlate to the theoretical group velocity. The final technique, the time domain reflectometer method, gave results which correspond to the theoretical group velocity but showed that the measured signal velocity will increase if a more sensitive detector is used. If the leading edge threshold of pulse modulated microwaves can be shown to propagate with the phase velocity, applications in rapid deep space communications would be possible. Potential applications include radar, sensing, remote control and satellite communications at velocities much greater than now possible.
Recommended Citation
Rolling, Thad G., "Velocity Measurement Techniques of Non-TEM Waves" (1995). Master's Theses (1922-2009) Access restricted to Marquette Campus. 4084.
https://epublications.marquette.edu/theses/4084